WASHINGTON: The United States is withdrawing from UNESCO, the United Nation's cultural and educational agency, effective Dec 31, the U.S. State Department said in a statement on Thursday.

"This decision was not taken lightly, and reflects U.S. concerns with mounting arrears at UNESCO, the need for fundamental reform in the organization, and continuing anti-Israel bias at UNESCO," the department said.

It added that the United States would seek to "remain engaged ...as a non-member observer state in order to contribute U.S. views, perspectives and expertise."

In response, UNESCO expressed regret over the decision.

"After receiving official notification by the United States Secretary of State, Mr Rex Tillerson, as UNESCO Director-General, I wish to express profound regret at the decision of the United States of America to withdraw from UNESCO," said UNESCO director general Irina Bokova in a statement.

Bokova added that the U.S. decision marked a loss for multilateralism and for the UN family.

The United States had cancelled its substantial budget contribution to UNESCO in 2011 in protest at a decision to grant the Palestinians full membership. --Reuters